CVE-2026-100811: Vulnerability in Mozilla Firefox
Sandbox escape due to use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17.
AI Analysis
Technical Summary
This vulnerability is a sandbox escape due to a use-after-free condition in the DOM: Core & HTML component of Mozilla Firefox. Such a flaw can allow code executing in a restricted environment to escape sandbox protections, potentially leading to unauthorized actions or code execution outside the intended sandbox. Mozilla fixed this vulnerability in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17. The vendor advisory lists this and related high-impact vulnerabilities fixed in these versions.
Potential Impact
The vulnerability enables sandbox escape, which can undermine the security boundaries of the browser and allow malicious code to execute with higher privileges or access restricted resources. This poses a significant security risk to users running affected versions of Firefox prior to the fixed releases.
Mitigation Recommendations
Users should update to Firefox ESR 153.4, Firefox 157, or Firefox ESR 140.17 or later to remediate this vulnerability. Mozilla has released official fixes for this issue. No additional mitigation steps are required beyond applying these updates.
CVE-2026-100811: Vulnerability in Mozilla Firefox
Description
Sandbox escape due to use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17.
CVSS v3.1
Score 9.6critical
Affected software
Mozilla
Firefox
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability is a sandbox escape due to a use-after-free condition in the DOM: Core & HTML component of Mozilla Firefox. Such a flaw can allow code executing in a restricted environment to escape sandbox protections, potentially leading to unauthorized actions or code execution outside the intended sandbox. Mozilla fixed this vulnerability in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17. The vendor advisory lists this and related high-impact vulnerabilities fixed in these versions.
Potential Impact
The vulnerability enables sandbox escape, which can undermine the security boundaries of the browser and allow malicious code to execute with higher privileges or access restricted resources. This poses a significant security risk to users running affected versions of Firefox prior to the fixed releases.
Mitigation Recommendations
Users should update to Firefox ESR 153.4, Firefox 157, or Firefox ESR 140.17 or later to remediate this vulnerability. Mozilla has released official fixes for this issue. No additional mitigation steps are required beyond applying these updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-26T19:18:10.767Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-100/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-97/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-99/","vendor":"Mozilla"}]
Threat ID: 6abbb3f5f7a7c541066409b3
Added to database: 09/29/2026, 12:49:57 UTC
Last enriched: 09/29/2026, 13:03:56 UTC
Last updated: 09/29/2026, 15:30:20 UTC
Views: 5
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